Doubt cast on MS cannabis treatment

 

There is no strong evidence to back the use of cannabis extract in the treatment of multiple sclerosis (MS), it was claimed.

A review of evidence on the first licensed preparation, Sativex, said there were "limitations" which made it difficult to identify the place of the product in clinical practice.

However the makers of the drug said they believed the comments gave a misleading view and that the review writers appeared to have misunderstood important elements of trials.

Sativex, in the form of a mouth spray, contains the principal extracts - dronabinol and cannabidiol - found in the leaf and flower of the cannabis plant, and is the first cannabinoid preparation to be licensed for use in the treatment of muscle spasms in MS.

The review, in the December issue of Drug and Therapeutics Bulletin (DTB), published by BMJ Journals, says MS is estimated to affect around 60,000 people in England and Wales, and around one in every 1,000 people will develop the condition in the UK.

An increase in muscle tone, or spasticity, is a common symptom of the condition, causing involuntary spasms, immobility, disturbed sleep, and pain.

Complex combinations of drugs are sometimes needed to manage spasticity, but they do not work that well and have a range of unpleasant side-effects, the DTB says.

Sativex is intended for use as a second-line treatment in patients in whom these other options have failed. But the review said the trial data on which the success of Sativex is based are limited.

Overall, the trials, on which the drug's approval was based, did show a small difference in the numbers of patients in whom symptoms abated compared with those taking a dummy (placebo) preparation, it said.

But in many of these studies, Sativex was used for relatively short periods - from six weeks to four months. And none included an active ingredient with which the effects of Sativex could be compared.

Two of the trials included doses that exceeded the 12 daily sprays for which the preparation is licensed, it said, and one trial did not have sufficient numbers of participants to validate the results.

A third trial, which was properly designed, and did have sufficient numbers of participants, did not find any significant difference in symptom relief between those who took Sativex and those who did not, it said.

The preparation is also expensive, it added, and costs around 10 times as much as other drugs used for the secondary treatment of MS muscle spasms.

The review says the strength of the evidence is insufficient to warrant its routine use. "We believe that such limitations make it difficult to identify the place of this product in clinical practice," it concludes.

GW Pharmaceuticals, the drug's maker, said: "We are disappointed with the conclusions drawn and strongly believe these comments give a misleading view of the drug."

A spokesman said the drug had been licensed in the UK by the Medicines and Healthcare Products Regulatory Agency (MHRA) in 2010.

Dr Stephen Wright, the company's research and development director, said: "The writers appear to have misunderstood important elements of the design of Sativex clinical trials and provide a flawed assessment of Sativex data.

"Furthermore, the article contradicts the opinion of 22 separate national authorities in Europe and around the world that have granted approval for Sativex and recognise the important benefits it provides to MS patients with spasticity."

The company said the review "fails to focus on clinical trials data which form the basis for Sativex' approval and which guide its use in clinical practice."

A spokesman said: "The key Phase III data on Sativex is robust and compelling, showed highly statistically significant results for the primary and all key secondary endpoints, and is entirely consistent with the dosing recommended in the product label."

He said the DTB "significantly overstates the price of daily Sativex treatment", adding: "Follow-up of all patients prescribed Sativex in the UK, covering more than 12,000 patient years, shows that the average daily dose in long-term clinical use is four sprays per day, a daily cost of £5.50. This is half the cost assumed by the DTB."

Ed Holloway, head of care and services research at the MS Society, said: "The MHRA has already looked at the evidence surrounding Sativex and has decided it is a safe and effective treatment for spasticity - otherwise it would not have been licensed.

"The MS Society believes the MHRA is the right organisation to be making that decision and this latest paper does not provide any new evidence; it simply looks at the same evidence the MHRA has already reviewed via a rigorous process.

"As such, we do not believe this work should call into question the MHRA's decision. Sativex works for some people and we want everyone with MS to have all possible treatment options available to them to combat the symptoms of the condition."

PA

Life and Style
ebookNow available in paperback
ebooks
ebookA delicious collection of 50 meaty main courses
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
SPONSORED FEATURES

ES Rentals

    Independent Dating
    and  

    By clicking 'Search' you
    are agreeing to our
    Terms of Use.

    iJobs Job Widget
    iJobs General

    Recruitment Genius: Senior Environmental Adviser - Maternity Cover

    £37040 - £43600 per annum: Recruitment Genius: The UK's export credit agency a...

    Recruitment Genius: CBM & Lubrication Technician

    £25000 - £27500 per annum: Recruitment Genius: This company provides a compreh...

    Recruitment Genius: Care Worker - Residential Emergency Service

    £16800 - £19500 per annum: Recruitment Genius: Would you like to join an organ...

    Recruitment Genius: Senior Landscaper

    £25000 - £28000 per annum: Recruitment Genius: In the last five years this com...

    Day In a Page

    The long walk west: they fled war in Syria, only to get held up in Hungary – now hundreds of refugees have set off on foot for Austria

    They fled war in Syria...

    ...only to get stuck and sidetracked in Hungary
    From The Prisoner to Mad Men, elaborate title sequences are one of the keys to a great TV series

    Title sequences: From The Prisoner to Mad Men

    Elaborate title sequences are one of the keys to a great TV series. But why does the art form have such a chequered history?
    Giorgio Armani Beauty's fabric-inspired foundations: Get back to basics this autumn

    Giorgio Armani Beauty's foundations

    Sumptuous fabrics meet luscious cosmetics for this elegant look
    From stowaways to Operation Stack: Life in a transcontinental lorry cab

    Life from the inside of a trucker's cab

    From stowaways to Operation Stack, it's a challenging time to be a trucker heading to and from the Continent
    Kelis interview: The songwriter and sauce-maker on cooking for Pharrell and crying over potatoes

    Kelis interview

    The singer and sauce-maker on cooking for Pharrell
    Refugee crisis: David Cameron lowered the flag for the dead king of Saudi Arabia - will he do the same honour for little Aylan Kurdi?

    Cameron lowered the flag for the dead king of Saudi Arabia...

    But will he do the same honour for little Aylan Kurdi, asks Robert Fisk
    Our leaders lack courage in this refugee crisis. We are shamed by our European neighbours

    Our leaders lack courage in this refugee crisis. We are shamed by our European neighbours

    Humanity must be at the heart of politics, says Jeremy Corbyn
    Joe Biden's 'tease tour': Could the US Vice-President be testing the water for a presidential run?

    Joe Biden's 'tease tour'

    Could the US Vice-President be testing the water for a presidential run?
    Britain's 24-hour culture: With the 'leisured society' a distant dream we're working longer and less regular hours than ever

    Britain's 24-hour culture

    With the 'leisured society' a distant dream we're working longer and less regular hours than ever
    Diplomacy board game: Treachery is the way to win - which makes it just like the real thing

    The addictive nature of Diplomacy

    Bullying, betrayal, aggression – it may be just a board game, but the family that plays Diplomacy may never look at each other in the same way again
    Lady Chatterley's Lover: Racy underwear for fans of DH Lawrence's equally racy tome

    Fashion: Ooh, Lady Chatterley!

    Take inspiration from DH Lawrence's racy tome with equally racy underwear
    8 best children's clocks

    Tick-tock: 8 best children's clocks

    Whether you’re teaching them to tell the time or putting the finishing touches to a nursery, there’s a ticker for that
    Charlie Austin: Queens Park Rangers striker says ‘If the move is not right, I’m not going’

    Charlie Austin: ‘If the move is not right, I’m not going’

    After hitting 18 goals in the Premier League last season, the QPR striker was the great non-deal of transfer deadline day. But he says he'd preferred another shot at promotion
    Isis profits from destruction of antiquities by selling relics to dealers - and then blowing up the buildings they come from to conceal the evidence of looting

    How Isis profits from destruction of antiquities

    Robert Fisk on the terrorist group's manipulation of the market to increase the price of artefacts
    Labour leadership: Andy Burnham urges Jeremy Corbyn voters to think again in last-minute plea

    'If we lose touch we’ll end up with two decades of the Tories'

    In an exclusive interview, Andy Burnham urges Jeremy Corbyn voters to think again in last-minute plea